Neptune is just one of two ice giants in our cosmic family, along with Uranus. It's blanketed in an atmosphere of hydrogen and helium, with traces of methane, water, and ammonia.

WASHINGTON, April 11 (Reuters) - Frigid and far-flung Neptune, our solar system's outermost planet, is adding to its reputation as an enigmatic world, with astronomers puzzled by a surprising drop ...

Neptune, a frigid planet decorated with supersonic storms, has been visited by only one spacecraft, Voyager 2, which zipped by in 1989.Consequently, little is definitively known about the planet ...

Over the past few years, the white clouds that usually shroud Neptune’s surface have disappeared, and it may be because of changes in the sun’s activity over its 11-year cycle ...

Frosty Neptune has an average of negative 340 degrees Fahrenheit (negative 220 degrees Celsius), and astronomers still don’t know what caused these temperature shifts.

Neptune's elliptical, oval-shaped orbit keeps the planet an average distance from the sun of almost 2.8 billion miles (4.5 billion kilometers), or roughly 30 times as far away as Earth, making it ...